Error in c++tools while building GCC 12.1.0 on HP-UX 11.23

["Matthew R. Wilson" <mwilson@mattwilson.org>]

Hello,

This may be a bit of stretch given that HP-UX 11.23 (11i v2) is a
bit...aged. But curious if anyone has any thoughts.

I am trying to build GCC 12.1.0 on HP-UX 11.23 on 64-bit PA-RISC.
(hppa64-hp-hpux11.23).

I current have GCC 6.5.0 (by way of HP ANSI C -> GCC 4.7.4 -> GCC 6.5.0)
with GNU binutils 2.38 (to provide as, since the GCC platforms page says
to use gas instead of the HP-UX as).

Stage 1 and Stage 2 appear to succeed. During Stage 3, I receive the
following:

   /home/mwilson/build/src/gcc-12.1.0/c++tools/server.cc:756:69: error:
   'readers' was not declared in this scope; did you mean 'readv'?
     756 | if (active < 0 && sock_fd >= 0 && FD_ISSET (sock_fd, &readers))
         |                                                       ^~~~~~~

With a bit more context:

$ make
...
make[2]: Entering directory '/home/mwilson/build/gcc-12.1.0_001/c++tools'
/home/mwilson/build/gcc-12.1.0_001/./gcc/xg++ -B/home/mwilson/build/gcc-12.1.0_001/./gcc/ -nostdinc++ `if test -f /home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/scripts/testsuite_flags; then /bin/sh /home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/scripts/testsuite_flags --build-includes; else echo -funconfigured-libstdc++-v3 ; fi` -L/home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/src -L/home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/src/.libs -L/home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/libsupc++/.libs -B/home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/src/.libs -B/home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/libsupc++/.libs -B/home/mwilson/bldutils64-gcc12.1.0/hppa64-hp-hpux11.23/bin/ -B/home/mwilson/bldutils64-gcc12.1.0/hppa64-hp-hpux11.23/lib/ -isystem /home/mwilson/bldutils64-gcc12.1.0/hppa64-hp-hpux11.23/include -isystem /home/mwilson/bldutils64-gcc12.1.0/hppa64-hp-hpux11.23/sys-include   -fchecking=1 -g -O2 -fno-exceptions -fno-rtti -I/home/mwilson/build/src/gcc-12.1.0/c++tools/../libcody -I/home/mwilson/build/src/gcc-12.1.0/c++tools/../include -I/home/mwilson/build/src/gcc-12.1.0/c++tools/../gcc -I. -I../gcc \
   -MMD -MP -MF server.d -c -o server.o /home/mwilson/build/src/gcc-12.1.0/c++tools/server.cc
In file included from /home/mwilson/build/gcc-12.1.0_001/gcc/include-fixed/sys/types.h:464,
                  from /home/mwilson/build/gcc-12.1.0_001/gcc/include-fixed/stdio.h:24,
                  from /home/mwilson/build/gcc-12.1.0_001/gcc/include-fixed/wchar.h:30,
                  from /home/mwilson/build/gcc-12.1.0_001/gcc/include-fixed/inttypes.h:707,
                  from /home/mwilson/build/gcc-12.1.0_001/gcc/include-fixed/stdint.h:27,
                  from /home/mwilson/build/gcc-12.1.0_001/gcc/include/stdint.h:9,
                  from /home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/include/bits/align.h:36,
                  from /home/mwilson/build/gcc-12.1.0_001/hppa64-hp-hpux11.23/libstdc++-v3/include/memory:72,
                  from /home/mwilson/build/src/gcc-12.1.0/c++tools/../libcody/cody.hh:24,
                  from /home/mwilson/build/src/gcc-12.1.0/c++tools/resolver.h:25,
                  from /home/mwilson/build/src/gcc-12.1.0/c++tools/server.cc:22:
/home/mwilson/build/src/gcc-12.1.0/c++tools/server.cc: In function 'void server(bool, int, module_resolver*)':
/home/mwilson/build/src/gcc-12.1.0/c++tools/server.cc:756:69: error: 'readers' was not declared in this scope; did you mean 'readv'?
   756 |               if (active < 0 && sock_fd >= 0 && FD_ISSET (sock_fd, &readers))
       |                                                                     ^~~~~~~
make[2]: *** [Makefile:84: server.o] Error 1

$ cat stage_current
stage3


Not sure if this is because HP-UX 11.23's system headers aren't
including something that's necessary (with GCC 6.5.0 I have a C++11
compiler, but I suspect HP-UX 11.23's libc isn't a C++11 stdlib...), or
if this is a solveable problem.

Alternatively, are these c++tools necessary? Can they be excluded from
the build?

My configure command was:

$ /home/mwilson/build/src/gcc-12.1.0/configure \
  --prefix=/home/mwilson/bldutils64-gcc12.1.0 \
  --enable-languages=c,c++ \
  --with-gnu-as --with-as=/home/mwilson/bldutils64-gcc6.5.0/bin/gas \
  --without-gnu-ld --with-ld=/usr/bin/ld \
  --enable-threads=posix

Thanks,
Matthew